Harley quote

Regarding two aftermarket power cables: "These differences in the shapes of the musical waveforms are far too small to see or measure with even the most sophisticated technology, yet we as listeners not only routinely discriminate such differences, we sometimes find musical meaning in these differences."

 Nonsense. Just because people claim to "routinely discriminate" differences doesn't mean it's true or they're right. Apparently many have witnessed UFOs but that doesn't mean they actually saw extraterrestrial visitors, does it? Some have seen/heard a deity speaking to them "routinely"; does that imply that they are surely communing with an unseen/unmeasurable spiritual force(s)? Can we not put a little more effort into confirmatory reality-testing first when "the most sophisticated technology" can find nothing in 2020? (Of course, speaker cables can measure differently as per here, here, even if not necessarily audible in many cases by the time we connect amp to speaker.)

Finding the right cord or cords for each piece of gear can make a bigger difference somtime than buying or upgrading it can be a much easier and less expensive route to take especially with a good dealer involved.
It is not hubris that I have forgot more about electrical engineering and physics than most of these cable charlatans know it's just fact based on their own writings.

Far greater than 50%? Is that 51%, 60%? because if the claimed substantial change is there it should be much > 75% not 50%. Were the levels matched to 0.1db,? How?

This concept of full loom to me is just silly and ignores the very real and substantial impact of component interaction as the only thing that will generate real sonic differences.

I am all for blind testing and I read the designer's (I assume) response under the review of above mentioned ABX Comparator...

"First of all, the capacitors, integrated circuits, diodes and resistors are not in the signal path at all."

What is the use for so much electronics in what is supposed to be an inert device?

Audio by Van Alstine ABX Comparator Review, Part 1: Audio Store & Wiring - Page 2 of 2 - Dagogo
Audio2sound, more like 80-90%. Read the article. 
I have a degree in Anthropology, Biology and a minor in Chemistry.  I am religious.  I also do not understand people who twist science or use yet to be discovered evidence as proof for Bible Stories.  Anyone with a true understanding of basic science would recognize crazy twisted tales supported by shoehorned data using “lack of evidence” as a main postulate for a proof.  I attended lectures by S J Gould regarding Punctuated Equilibrium.  Brilliant man....not a religious, former geologist for Chevron, but smart.  Oh, and let’s not forget Peer Review....oops!